I do not see any blue highlighted nor red items like it usually shows. I'm positive there is a transparent item; I was messing with a WaterHorse AO which requires laying out the AO, using CTRL>ALT>T to find the AO, then edit it. Highlight Transparent DOES work, which I found very relieving during this project, it just seems to be the shortcut that isn't working. I may have indeed changed keyboard mappings, though I wouldn't know where or when.